The hydraulic gangway systems or "Walk to Work" as they are commonly known in the industry are indeed a good sollution for getting people sefely from vessels onto rigs and I was personally involved in 4 such charters this year, 3 of which are ongoing. There are two main systems in use at the moment, the Amplemann system and the Offshore Access Sollutions system, there is also a 3rd system just arrived from Uptime but its largly unproven at this time.
The problem is however that these take time to mobilse, they are by no means plug and play systems and each has to have design approvals for any vessel they are mobilised onto. You also have the issue of vertical reach for rigs and in some cases large platforms need to be designed, constructed and installed onto the vessels deck to give the required vertical reach, the last one of these took about 3months from design to approval.
The MCA also threw a spanner in the works this year by declaring that any vessels to be used for passenger transfer / walk to work duties need to comply with SPS 2008 coding otherwise they are limited to carrying a maximum of 12 passengers. This has led to the crazy situation where vessels doing walk to work all last season have not been allowed to do so again this season and the market is currently pretty much sold out for SPS coded vessels.
We did have a situation a few weeks ago due to the backlog caused by the fog where the MCA were issuing waivers on a voyage by voyage basis to allow passenger transferes and there are rumours they may be about to relax the rules in the next day or two given this unfortunate incident.
You are then however back to having to do FROG transfers for at least several weeks until Walk to Work systems can be mobilised onto vessels and there is no 'fast track' sollution for this, not if you want it done safely. Shell, BP, Talisman and Chevron have one vessel each with a gangway already in place but these vessels are already tied into offshore maintenance scopes, the BP vessel only has about 40 spare beds anyway, thats hardly going to make a dent.
Also as we approach the winter and the weather picks up walk to work and FROG's will be off the table given their limited weather operating criteria. Its going to be a tricky situation for the Bears and it may be that the only sollution in the interim is longer durations between crewchanges.
UA